Question

Convert 20 µg/dL Pb in blood to ppm. Please assume density of blood is 1 g/mL

Answer 1

Answer:- 0.0002 ppm

Solution:- 1 ppm is one mg of solute per liter of solvent or one kg of solvent.

It asks to convert $\frac{20\mu g}{dL}$ pb in blood to ppm. density of blood is $\frac{1g}{mL}$ .

Let's convert micrograms to milligrams and also calculate the mass of blood from it's given density. The set up could be made using dimensional analysis and doing unit conversions as:

First the set up for the conversion of micrograms of Pb to milligrams:

$\frac{20\mu g}{dL}(\frac{0.001mg}{1\mu g})$

= $\frac{0.02mg}{dL}$

Now, the set up for converting dL of blood to kg using it's given density and unit conversion from dL to mL as:

$\frac{0.02mg}{dL}(\frac{0.01dl}{1mL})(\frac{1mL}{1g})(\frac{1000g}{1kg})$

= 0.200 ppm